LEUCOCYTES
DR.SUNDARESAN
PATHOLOGY
LOYOLA COLLEGE
SPECIFIC LEARNING
OBJECTIVES
 At the end of the class the student must be able to
 Decribe the normal values functions of leucocytes
 Explain the RES (Reticulo endothelial system)
WBC
 WBC differ from RBC – Hb and nucleus
 Ratio RBC and WBC – 600:1
 Total leucocyte range – 4000 – 11000 / mm3
CLASSIFICATION
WBC
Granulocytes Agranulocytes
Neutrophil Eosinophil Basophil Monocyte Lymphocyte
NORMAL VALUES
Total count – adults – 4000 – 11,000 cells/cu.mm.
- at birth 10,000 – 25,000 cells/cu.mm.
Cell Differential
Count
Absolute count
(cells/cu.mm.)
Neutrophil 50 – 70% 2000 – 7000
Eosinophil 1 – 4% 50 – 500
Basophil 0 – 1% 10 – 100
Monocyte 2 – 8% 200 – 800
Lymphocyte 20 – 40% 1500 - 4000
GRANULOCYTES
 GRANULOPOIESIS – production and maturation of
granulocytes
 SITE OF FORMATION
 Before birth – mesoderm, liver & spleen
 After birth – red bone marrow
 During development – granulocytes lose their capacity
to divide and attain specific morphological features –
finally develop into functionally competent cells
STAGES OF
GRANULOPOIESIS
Haemocytoblast/pluripotent cell/non
Committed stem cell
Committed stem cell
Myeloblast
Promyelocyte
Myelocyte
Metamyelocyte
Matured granulocytes
REGULATION OF
GRANULOPOIESIS
 The following factors stimulate the granulopoiesis
 The rate of production mainly depends on the
concentration of these factors
 Granulocyte-macrophage colony stimulating factor
(GM-CSF)
 Granulocyte colony stimulating factor (G-CSF)
 Macrophage colony stimulating factor (M-CSF)
 IL-1
 IL-3
 IL-6
 Tumour necrosis factor
 Fibroblasts
 Endothelial cells
 T-lymphocytes
FUNCTIONS OF
NEUTROPHILLS
 1.PHAGOCYTOSIS OF BACTERIA
 These are the frontline soldiers
 DIAPEDESIS
 The circulating cells become marginated
 The cells come out by squeezing through the pores of
the capillary wall and
 Enters the tissue
 CHEMOTAXIS
 These are attracted to the site of infection by certain
chemicals released from the site of infection
 OPSONISATION
 Once the cells reach the site – neutrophills start
engulfing the bacteria
 Complements and antibodies get attached to the
bacteria
 These are called opsonins
 The process is called opsonosation
 Opsonisation facilitates phagocytosis
 Ca++ ion is required for this process
 First the cell membrane of neutrophil becomes
invaginated until the bacterium is completely engulfed
 Then, the digestive pouch called phagosome is formed
 This is merged with a lysozome containing hydrolyzing
enzyme and bacterial agents like h2o2,
myeloperoxidase, lysozyme, lactoferrin
 These enzymes kill and digest the bacterium
 A neutrophil can phagocytize 5-20 bacteria
 2.phagocytosis of antigen-antibody complexes
 This prevents the harmful reactions that develop due
to antigen-antobody reaction
 3.phagocytosis of dead cells, foreign particles like
carbon particles, sodium urate crystals
 In other words – neutrophills act as a scavengers
 Microphages – phagocitize small particles
Applied aspects  Neutrophilia
Physiological Pathological
Exercise
Pregnancy
Parturition
Emotional stress
Acute pyogenic infections
Rheumatic fever
Myocardial infarction
↓ Neutropenia
Physiological Pathological
Rare
Exposure to cold
Typhoid
Paratyphoid
Aplastic anemia
Viral infection -measles
ARNETH COUNT
N1 N2
N3
N4
N5
EOSINOPHILLS
 These are abundant in the mucosa of GIT, urinary and
respiratory tract
 Their maturation is stimulated by IL-3, IL-5, GM-CSF
 FUNCTIONS
 Have role in clot lysis – they produce prefibrinolysin
 Engulf antigen-antobody complexex – and thereby
prevent more release of vasoactive substanced
 It participate in antiallergic role – these contains anti-
inflammatory histaminases and aryl-sulfatase – which
inactivate histamine and SRS-A
 They have a role in detoxification of certain foreighn
proteins
 A basic proteins present in eosinophills – destroys
larval parasites
 Eosinophillic cationic proteins (ECP) – act as
bactericidal and larvicidal
Eosinophil
 Eosinophilia ↓ Eosinopenia
Allergic conditions
arasitic infestations
Skin diseases
ACTH therapy
Acute pyogenic infec
Aplastic anemia
BASOPHILLS
 It produces heparin – this helps in prevention of
intravascular clotting
 It also contains histamine SRS-A and eosinophillic
chemotactic factor
 So, it may participate in allergic reactions along with
mast cells – like urticaria, rhinitis and anaphylactic
shock
 Participate in lipid metabolism
Basophil
 Basophilia ↓ Basophilopenia
Chronic myeloid leukemia
Polycythemia
Rare
Aplastic anemia
AGRANULOCYTES
 LYMPHOCYTES – produced from bone marrow and
lymphoid tissue
 MONOCYTES – produced from bone marrow and liver
LYMPHOCYTES
B LYMPHOCYTES
 20 %
 Produce antibodies
 Bone marrow
 Humoral immunity
 Bacterial infections
T LYMPHOCYTES
 80%
 Produce chemicals called
cytokines
 Thymus
 Cell mediated
 Viral infections
LYMPHOCYTES
B LYMPHOCYTES
 Shorter life span
 Class II MHC present on
membrane
 Have immunoglobulins
 Agammaglobulinaemia
 Multiple myeloma
T LYMPHOCYTES
 Longer life span
 Absent
 Absent
 AIDS
 Various autoimmune
diseases
Lymphocyte
 Lymphocytosis ↓ Lymphocytopenia
Chronic infections
Infectious Mononucleosis
Lymphoma
Viral infection
Immunosuppressive therapy
ACTH therapy
Hodgkin’s disease
Bone marrow failure
MONOCYTE(BLOOD
MACROPHAGES)
 FUNCTIONS
 These enters the tissue and form the tissue
macrophages and act as scavengers
 Phagocitize several bacteria
 Engulf large particulate matter, dead tissue cells and
senile cells
 Monocyte along with other macrophages involved in
phagocytosis and destruction of necrotic material
 Participate in humoral and cellular immunity
Monocyte
 Monocytosis ↓ Monocytopenia
Malaria
Kala-azar
Monocytic leukemia
Rare
Bone marrow failure
Aplastic anemia
RETICULOENDOTHELIAL SYSTEM
Monocyte macrophage system(MMS)
Mononuclear phagocytic system (MPS)
 Generalised phagocytic system
 Special group of cells scattered in different parts
• Powerful phagocytes
• Stained by supravital stains
 Monocytes – macrophages
 Liver – Kupffer cells
 CNS – Microglia
 Lungs – Alveolar macrophages
 Skin – Langerhans cells
 Bone – Osteoclasts
 Lymph nodes, spleen & bone marrow – Dendritic cells
 Connective tissue – Histiocytes [Fixed & wandering]
Functions of RES
 More powerful phagocytic action than Neutrophil
 Engulf larger particle
 Engulf more numbers (100)
 Survive even after ingestion of bacteria
 Ingest & destroy RBC & release bilirubin
 Also destroy dead WBC’s & platelets
 Ingest & process antigen & present it to Lymphocyte(play
a role in Immunity)
 Produce IL-1-activates T cell
CSF-GM-regulates erythropoiesis
 Initiate development of antibody
 Activated by lymphokines of T lymphocytes.Migrate to
area of inflammation & engulf bacteria
 Sites of hemopoiesis during fetal life(spleen & liver)

Leucocytes

  • 1.
  • 2.
    SPECIFIC LEARNING OBJECTIVES  Atthe end of the class the student must be able to  Decribe the normal values functions of leucocytes  Explain the RES (Reticulo endothelial system)
  • 3.
    WBC  WBC differfrom RBC – Hb and nucleus  Ratio RBC and WBC – 600:1  Total leucocyte range – 4000 – 11000 / mm3
  • 4.
  • 5.
    NORMAL VALUES Total count– adults – 4000 – 11,000 cells/cu.mm. - at birth 10,000 – 25,000 cells/cu.mm. Cell Differential Count Absolute count (cells/cu.mm.) Neutrophil 50 – 70% 2000 – 7000 Eosinophil 1 – 4% 50 – 500 Basophil 0 – 1% 10 – 100 Monocyte 2 – 8% 200 – 800 Lymphocyte 20 – 40% 1500 - 4000
  • 8.
    GRANULOCYTES  GRANULOPOIESIS –production and maturation of granulocytes  SITE OF FORMATION  Before birth – mesoderm, liver & spleen  After birth – red bone marrow  During development – granulocytes lose their capacity to divide and attain specific morphological features – finally develop into functionally competent cells
  • 9.
    STAGES OF GRANULOPOIESIS Haemocytoblast/pluripotent cell/non Committedstem cell Committed stem cell Myeloblast Promyelocyte Myelocyte Metamyelocyte Matured granulocytes
  • 10.
    REGULATION OF GRANULOPOIESIS  Thefollowing factors stimulate the granulopoiesis  The rate of production mainly depends on the concentration of these factors  Granulocyte-macrophage colony stimulating factor (GM-CSF)  Granulocyte colony stimulating factor (G-CSF)  Macrophage colony stimulating factor (M-CSF)
  • 11.
     IL-1  IL-3 IL-6  Tumour necrosis factor  Fibroblasts  Endothelial cells  T-lymphocytes
  • 12.
    FUNCTIONS OF NEUTROPHILLS  1.PHAGOCYTOSISOF BACTERIA  These are the frontline soldiers  DIAPEDESIS  The circulating cells become marginated  The cells come out by squeezing through the pores of the capillary wall and  Enters the tissue
  • 13.
     CHEMOTAXIS  Theseare attracted to the site of infection by certain chemicals released from the site of infection  OPSONISATION  Once the cells reach the site – neutrophills start engulfing the bacteria  Complements and antibodies get attached to the bacteria
  • 14.
     These arecalled opsonins  The process is called opsonosation  Opsonisation facilitates phagocytosis  Ca++ ion is required for this process  First the cell membrane of neutrophil becomes invaginated until the bacterium is completely engulfed
  • 15.
     Then, thedigestive pouch called phagosome is formed  This is merged with a lysozome containing hydrolyzing enzyme and bacterial agents like h2o2, myeloperoxidase, lysozyme, lactoferrin  These enzymes kill and digest the bacterium  A neutrophil can phagocytize 5-20 bacteria
  • 17.
     2.phagocytosis ofantigen-antibody complexes  This prevents the harmful reactions that develop due to antigen-antobody reaction  3.phagocytosis of dead cells, foreign particles like carbon particles, sodium urate crystals  In other words – neutrophills act as a scavengers  Microphages – phagocitize small particles
  • 18.
    Applied aspects Neutrophilia Physiological Pathological Exercise Pregnancy Parturition Emotional stress Acute pyogenic infections Rheumatic fever Myocardial infarction
  • 19.
    ↓ Neutropenia Physiological Pathological Rare Exposureto cold Typhoid Paratyphoid Aplastic anemia Viral infection -measles
  • 20.
  • 21.
    EOSINOPHILLS  These areabundant in the mucosa of GIT, urinary and respiratory tract  Their maturation is stimulated by IL-3, IL-5, GM-CSF  FUNCTIONS  Have role in clot lysis – they produce prefibrinolysin  Engulf antigen-antobody complexex – and thereby prevent more release of vasoactive substanced
  • 22.
     It participatein antiallergic role – these contains anti- inflammatory histaminases and aryl-sulfatase – which inactivate histamine and SRS-A  They have a role in detoxification of certain foreighn proteins  A basic proteins present in eosinophills – destroys larval parasites  Eosinophillic cationic proteins (ECP) – act as bactericidal and larvicidal
  • 23.
    Eosinophil  Eosinophilia ↓Eosinopenia Allergic conditions arasitic infestations Skin diseases ACTH therapy Acute pyogenic infec Aplastic anemia
  • 24.
    BASOPHILLS  It producesheparin – this helps in prevention of intravascular clotting  It also contains histamine SRS-A and eosinophillic chemotactic factor  So, it may participate in allergic reactions along with mast cells – like urticaria, rhinitis and anaphylactic shock  Participate in lipid metabolism
  • 25.
    Basophil  Basophilia ↓Basophilopenia Chronic myeloid leukemia Polycythemia Rare Aplastic anemia
  • 26.
    AGRANULOCYTES  LYMPHOCYTES –produced from bone marrow and lymphoid tissue  MONOCYTES – produced from bone marrow and liver
  • 27.
    LYMPHOCYTES B LYMPHOCYTES  20%  Produce antibodies  Bone marrow  Humoral immunity  Bacterial infections T LYMPHOCYTES  80%  Produce chemicals called cytokines  Thymus  Cell mediated  Viral infections
  • 28.
    LYMPHOCYTES B LYMPHOCYTES  Shorterlife span  Class II MHC present on membrane  Have immunoglobulins  Agammaglobulinaemia  Multiple myeloma T LYMPHOCYTES  Longer life span  Absent  Absent  AIDS  Various autoimmune diseases
  • 29.
    Lymphocyte  Lymphocytosis ↓Lymphocytopenia Chronic infections Infectious Mononucleosis Lymphoma Viral infection Immunosuppressive therapy ACTH therapy Hodgkin’s disease Bone marrow failure
  • 30.
    MONOCYTE(BLOOD MACROPHAGES)  FUNCTIONS  Theseenters the tissue and form the tissue macrophages and act as scavengers  Phagocitize several bacteria  Engulf large particulate matter, dead tissue cells and senile cells
  • 31.
     Monocyte alongwith other macrophages involved in phagocytosis and destruction of necrotic material  Participate in humoral and cellular immunity
  • 32.
    Monocyte  Monocytosis ↓Monocytopenia Malaria Kala-azar Monocytic leukemia Rare Bone marrow failure Aplastic anemia
  • 33.
    RETICULOENDOTHELIAL SYSTEM Monocyte macrophagesystem(MMS) Mononuclear phagocytic system (MPS)  Generalised phagocytic system  Special group of cells scattered in different parts • Powerful phagocytes • Stained by supravital stains  Monocytes – macrophages  Liver – Kupffer cells  CNS – Microglia  Lungs – Alveolar macrophages  Skin – Langerhans cells  Bone – Osteoclasts  Lymph nodes, spleen & bone marrow – Dendritic cells  Connective tissue – Histiocytes [Fixed & wandering]
  • 34.
    Functions of RES More powerful phagocytic action than Neutrophil  Engulf larger particle  Engulf more numbers (100)  Survive even after ingestion of bacteria  Ingest & destroy RBC & release bilirubin  Also destroy dead WBC’s & platelets  Ingest & process antigen & present it to Lymphocyte(play a role in Immunity)  Produce IL-1-activates T cell CSF-GM-regulates erythropoiesis  Initiate development of antibody  Activated by lymphokines of T lymphocytes.Migrate to area of inflammation & engulf bacteria  Sites of hemopoiesis during fetal life(spleen & liver)